#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>

int DefStrlen(char* a)
{
	int b = 0;
	while (*a++)
	{
		b++;
	}
	return b;
}

int main()
{
	char a [] = "abcdefghi";
	int b = DefStrlen(a);
	printf("%d", b);
	return 0;
}